Equalizer with lubrication

ABSTRACT

An equalizer for a mining machine includes an equalizer main body, an internal chamber defined by the main body configured to retain lubrication, and a bushing disposed within the internal chamber. The bushing includes an opening. The equalizer further includes a pin disposed partially in the internal chamber and extending through the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/437,952, filed Dec. 22, 2016, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to the field of earthmoving machines.Specifically, the present invention relates to an equalizer for a miningshovel.

A conventional rope mining shovel includes a boom, a handle moveablycoupled to the boom, a dipper that is coupled to the handle, anequalizer that is coupled to the dipper, and a hoist rope that iscoupled to the equalizer. The hoist rope passes over a boom sheavecoupled to an end of the boom, and is reeled in and paid out by a hoistdrum. The equalizer aligns the hoist rope to be tangent to the boomsheave, reducing wear on the rope. The equalizer is a plate fabrication,having a plurality of apertures and windows for weld access.

During a hoist phase, the rope is reeled in by the hoist drum, liftingthe dipper upward through a bank of material and liberating the materialto be dug. To release the material disposed within the dipper, a dipperdoor is pivotally coupled to the dipper. When not latched to the dipper,the dipper door pivots away from a bottom of the dipper, thereby freeingthe material out through a bottom of the dipper.

SUMMARY

In accordance with one construction, an equalizer for a mining machineincludes an equalizer main body that is a single cast piece, an internalchamber defined by the main body configured to retain lubrication, and abushing disposed within the internal chamber. The bushing includes anopening. The equalizer further includes a pin disposed partially in theinternal chamber and extending through the opening.

In accordance with another construction, an equalizer for a miningmachine includes an equalizer main body, an internal chamber defined bythe main body, a bushing disposed within the internal chamber, thebushing including an opening configured to receive a pin, a pinextending through the opening, an end cap coupled to the main body, asealing structure coupled to the end cap and pressed against the pin,and lubrication sealed within the internal chamber.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a mining shovel according to one construction.

FIG. 2 is a perspective view of a dipper of the mining shovel of FIG. 1,and an equalizer coupled to a dipper.

FIGS. 3 and 4 are side and perspective cross-sectional views,respectively, of one end of the equalizer, illustrating sealingstructures that hold lubrication within the equalizer.

FIGS. 5 and 6 are side and perspective cross-sectional views of anequalizer according to another construction.

FIGS. 7-9 are perspective, cross-sectional views of an equalizeraccording to another construction.

Before any constructions of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other constructions and of being practicedor of being carried out in various ways. Also, it is to be understoodthat the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

DETAILED DESCRIPTION

FIG. 1 illustrates a power shovel 10. The shovel 10 includes a mobilebase 15, drive tracks 20, a turntable 25, a revolving frame 30, a boom35, a lower end 40 of the boom 35 (also called a boom foot), an upperend 45 of the boom 35 (also called a boom point), tension cables 50, agantry tension member 55, a gantry compression member 60, a sheave 65rotatably mounted on the upper end 45 of the boom 35, a dipper 70, adipper door 75 pivotally coupled to the dipper 70, hoist ropes 80 (oneshown), a winch drum (not shown), a dipper handle 85, a saddle block 90,a shipper shaft 95, and a transmission unit (also called a crowd drive,not shown). The rotational structure 25 allows rotation of the upperframe 30 relative to the lower base 15. The turntable 25 defines arotational axis 100 of the shovel 10. The rotational axis 100 isperpendicular to a plane 105 defined by the base 15 and generallycorresponds to a grade of the ground or support surface.

The mobile base 15 is supported by the drive tracks 20. The mobile base15 supports the turntable 25 and the revolving frame 30. The turntable25 is capable of 360-degrees of rotation relative to the mobile base 15.The boom 35 is pivotally connected at the lower end 40 to the revolvingframe 30. The boom 35 is held in an upwardly and outwardly extendingrelation to the revolving frame 30 by the tension cables 50, which areanchored to the gantry tension member 55 and the gantry compressionmember 60. The gantry compression member 60 is mounted on the revolvingframe 30.

The dipper 70 is suspended from the boom 35 by the hoist ropes 80. Thehoist ropes 80 are wrapped over the sheave 65 and are coupled to anequalizer 110, which is coupled to the dipper 70. The hoist ropes 80 areanchored to the winch drum (not shown) of the revolving frame 30. Thewinch drum is driven by at least one electric motor (not shown) thatincorporates a transmission unit (not shown). As the winch drum rotates,the hoist ropes 80 are paid out to lower the dipper 70 or pulled in toraise the dipper 70. The dipper handle 85 is also coupled to the dipper70. The dipper handle 85 is slidably supported in the saddle block 90,and the saddle block 90 is pivotally mounted to the boom 35 at theshipper shaft 95. The dipper handle 85 includes a rack and toothformation thereon that engages a drive pinion (not shown) mounted in thesaddle block 90. The drive pinion is driven by an electric motor andtransmission unit (not shown) to extend or retract the dipper handle 85relative to the saddle block 90.

An electrical power source (not shown) is mounted to the revolving frame30 to provide power to a hoist electric motor (not shown) for drivingthe hoist drum, one or more crowd electric motors (not shown) fordriving the crowd transmission unit, and one or more swing electricmotors (not shown) for turning the turntable 25. Each of the crowd,hoist, and swing motors is driven by its own motor controller, or isalternatively driven in response to control signals from a controller(not shown).

With reference to FIG. 2, the dipper 70 includes a first matingprojection 115 (e.g., a lug) and a second mating projection 120 (e.g., alug) that each extend from a back wall 125 of the dipper 70. Theequalizer 110 is generally disposed between and is coupled to the firstand second mating projections 115, 120.

With reference to FIGS. 2-4, the equalizer 110 includes a main body 130that is a single cast piece having a first end 135 and an opposite,second end 140. The cast piece does not include apertures or holes forweld access. As illustrated in FIGS. 3 and 4, the main body 130 definesan internal chamber 145 that is open at the first end 135. The chamber145 is formed during the casting process. A pin 150 extends through thefirst end 135 and into the open chamber 145. In the illustratedconstruction, the pin 150 is an induction hardened pin having an end 155that projects out of the main body 130 and fits into one of the firstand second mating projections 115, 120. Other constructions includedifferent types, shapes, and sizes of pins 150 than that illustrated.

With continued reference to FIGS. 3 and 4, the equalizer 110 includes abushing 160 disposed within the chamber 145. The bushing 160 includes anopening 165 to receive the pin 150, and to facilitate rotation of thepin 150 relative to the main body 130. In the illustrated constructionthe bushing 160 is a standard manganese bushing, although otherconstructions include different bushings. For example, in someconstructions the bushing 160 is a plain spherical bushing.

With continued reference to FIGS. 3 and 4, the equalizer 110 includes anend cap 170 coupled to the first end 135 of the main body 130. In theillustrated construction, the end cap 170 is a generally disc-likestructure having an outer diameter that is identical or substantiallyidentical to an outer diameter of the first end 135 of the main body130. However, other constructions include different shapes and sizesthan that illustrated.

As illustrated in FIGS. 3 and 4, the end cap 170 includes an outercircumferential surface 175 that faces away from the first end 135, anda smaller, inner circumferential surface 180 that faces toward the firstend 135. In the illustrated construction, a first sealing structure 185(e.g., polyurethane, etc.) is provided along the inner circumferentialsurface 180 within a circumferential notch 190 in the end cap 170. Whenthe end cap 170 is coupled to the main body 130 (e.g., with fasteners orother structures), the first sealing structure 185 presses against thefirst end 135, thereby sealing the end cap 170 to the main body 130.

With continued reference to FIGS. 3 and 4, the end cap 170 furtherincludes a recess 195 defined by a first circumferential surface 200that extends transverse to both the outer circumferential surface 175and the inner circumferential surface 180, and a second circumferentialsurface 205 that extends parallel to both the outer circumferentialsurface 175 and the inner circumferential surface 180. The recess 195extends circumferentially about the pin 150.

With continued reference to FIGS. 3 and 4, the equalizer 110 includes aseal carrier 210 disposed at least partially within the recess 195. Theseal carrier 210 includes a carrier body 215, and a second sealingstructure 220 (e.g., polyurethane, etc.) provided within acircumferential notch 225 in the carrier body 215. The second sealingstructure 220 is a piston seal that presses against the pin 150, therebysealing the seal carrier 210 to the pin 150. As illustrated in FIGS. 3and 4, the seal carrier 210 is a floating radial seal, in that thereremains a radial gap 230 in the recess 195 between the carrier body 215and the first circumferential surface 200. The seal carrier 210therefore “floats” within the recess 195, and remains sealed against thepin 150 even if the bushing 160, for example, experiences radial wear(e.g., in some instances up to an inch) and the pin 150 deflectsradially in one direction.

With continued reference to FIGS. 3 and 4, the end cap 170 furtherincludes a third sealing structure 235 (e.g., polyurethane, etc.) thatis provided within a circumferential notch 240 along the secondcircumferential surface 205. The third sealing structure 235 is a faceseal that presses against the carrier body 215 of the seal carrier 210,thereby sealing the end cap 170 to the seal carrier 210.

With continued reference to FIGS. 3 and 4, the equalizer 110 includeslubrication 245 (illustrated schematically in FIG. 3 generally as a poolor collection of lubrication within at least a portion of the internalchamber 145). In some constructions, the lubrication 245 is oil,although other constructions include different types of lubrication(e.g., grease, etc.). The lubrication 245 is free to flow, for example,around and alongside the pin 150, and into spaces between the pin 150and the bushing 160 and generally throughout the internal chamber 145.

While only one end of the equalizer 110 is illustrated in FIGS. 3 and 4,the equalizer 110 of the illustrated construction is symmetrical about aplane extending transverse to an axis 250 (FIG. 3) that passes throughboth the first and second ends 135, 140 and through the pin 150. Thus,all of the features illustrated in FIGS. 3 and 4 are also present at anopposite end of the equalizer 110, such that the internal chamber 145 isan internal, central space within the equalizer 110 that is large enoughto contain lubrication 245 for lubricating bushings 160 at both ends ofthe equalizer 110.

With continued reference to FIGS. 3 and 4, the first sealing structure185, the second sealing structure 220, and the third sealing structure235 work in conjunction to seal the lubrication 245 within the equalizer110 and within the internal chamber 145. Thus, even if the lubrication245 flows axially past the bushing 160, the lubrication 245 will beinhibited or prevented from escaping past the end cap 170.

In some constructions, the lubrication 245 moves from one end of theequalizer 110 to the other, or from one location in the equalizer 110 toanother, based purely on movement of the shovel 10 itself, or uponmovement of the pin 150 and the main body 130. Thus, at least in someconstructions, the equalizer 110 does not include a mechanism togenerate movement of the lubrication 245. Additionally, the lubrication245 slows the wear of the bushing 160, the pin 150, and/or of othercomponents and surfaces within the equalizer 110. Thus, the equalizer110 requires less maintenance and down-time as compared with anequalizer 110 without the added lubrication 245.

FIGS. 5 and 6 illustrate an equalizer 310 according to anotherconstruction. Similar to the equalizer 110, the equalizer 310 includes amain body 330 that is a single cast piece having a first end 335 and anopposite end (not shown). The main body 330 defines an internal chamber345 that is open at the first end 335. The internal chamber 345 isformed during the casting process. A pin 350 extends through the firstend 335 and into the open chamber 345. The equalizer 310 also includes abushing 360 disposed within the chamber 345. The bushing 360 includes anopening 365 to receive the pin 350, and to facilitate rotation of thepin 350 relative to the main body 330. The equalizer 310 also includesan end cap 370 coupled to the first end 335 of the main body 330. Theend cap 370 includes an outer circumferential surface 375 that facesaway from the first end 335, and a smaller, inner circumferentialsurface 380 that faces toward the first end 335. The end cap 370 furtherincludes a recess 395 defined by a first circumferential surface 400that extends transverse to both the outer circumferential surface 375and the inner circumferential surface 380, and a second circumferentialsurface 402 that extends parallel to both the outer circumferentialsurface 375 and the inner circumferential surface 380. The recess 395extends circumferentially about the pin 350.

With continued reference to FIGS. 5 and 6, the equalizer 310 includes asealing structure 405 disposed at least partially within the recess 395.In the illustrated construction, the sealing structure 405 includes acorrugated, polyurethane body 410 that is coupled (e.g., vulcanized) ata first, radial outer end 415 (FIG. 6) to the first circumferentialsurface 400, and is coupled (e.g., vulcanized) at a second, radial innerend 420 (FIG. 6) to a metal rail 425. In the illustrated constructionthe metal rail 425 has a U-shaped cross-section defining a notch 430.The notch is sized and shaped to receive a further sealing structure(e.g., polyurethane, etc. not shown), which extends out of the notch 430and presses against the pin 350.

With continued reference to FIGS. 5 and 6, the equalizer 310 alsoincludes lubrication (not shown) disposed within the internal chamber345 of the main body 330. In some constructions, the lubrication is oil,although other constructions include different types of lubrication(e.g., grease, etc.). The lubrication is free to flow alongside the pin350, and into spaces between the pin 350 and the bushing 360.

With continued reference to FIGS. 5 and 6, the sealing structure 405(and further sealing structure) seals the lubrication within theequalizer 310 and within the internal chamber 345. Thus, even if thelubrication 445 flows axially past the bushing 360, the lubrication 445will be inhibited or prevented from escaping past the end cap 370.

Similar to the equalizer 110, in the equalizer 310 all of the featuresillustrated in FIGS. 5 and 6 are also present at an opposite end of theequalizer 310, such that the internal chamber 345 is an internal,central space within the equalizer 310 that is large enough to containlubrication for lubricating bushings 360 at both ends of the equalizer310.

FIGS. 7-9 illustrate an equalizer 510 according to another construction.Similar to the equalizers 110 and 310, the equalizer 510 includes a mainbody 530 that is a single cast piece having a first end 535 and anopposite end (not shown). The main body 530 defines an internal chamber545 that is open at the first end 535. The internal chamber 545 isformed during the casting process. A pin 550 extends through the firstend 535 and into the open chamber 545. The equalizer 510 also includes abushing 560 disposed within the chamber 545. The bushing 560 includes anopening 565 to receive the pin 550, and to facilitate rotation of thepin 550 relative to the main body 530. The equalizer 510 also includesan end cap 570 coupled to the first end 535 of the main body 530. Theend cap 570 includes a thrust plate 574 and a radial seal (e.g.,elastomeric) 578 coupled to the thrust plate 574. In the illustratedconstruction, the thrust plate 574 is formed at least partially fromMoS₂, and includes mounting apertures 582 for insertion of screws orother fasteners to affix the thrust plate 574 to the main body 530.Other constructions include different materials, as well as differentlocations for mounting apertures 582 than that illustrated. Asillustrated in FIG. 8, the equalizer 510 also includes a garter spring586 that assists in pressing the radial seal 578 against the pin 550,and an O-ring 590 that is coupled to a radially exterior surface 594 ofthe thrust plate 574.

With reference to FIG. 9, in the illustrated construction, the equalizer510 further includes a spacer element 598 (illustrated schematically)disposed within the internal chamber 545 at the first end 535. Thespacer element 598 is disposed between the end cap 570 and the bushing560. The spacer element 598 may be welded in place or otherwise insertedand/or affixed in place, such that the spacer element 598 inhibits orprevents the bushing 560 from moving and sliding toward the radial seal578. In the illustrated construction, the spacer element 598 is a spacerplate. In other constructions, the spacer element 598 is a snap ring,rope bead (e.g., welded to an inside of the equalizer main body 530), orother element that inhibits or prevents the bushing 560 from moving andsliding toward the radial seal 578.

While various constructions of sealing structures have been describedabove for the equalizers 110, 310, 510, in other constructions theequalizers 110, 310, 510 include other sealing structures orcombinations of sealing structures (e.g., O-rings, gaskets, etc.) toseal lubrication within the equalizer 110, 310, 510.

Although the invention has been described in detail with reference tocertain preferred constructions, variations and modifications existwithin the scope and spirit of one or more independent aspects of theinvention as described.

What is claimed is:
 1. An equalizer for a mining machine, the equalizercomprising: an equalizer main body; an internal chamber defined by themain body; a bushing disposed within the internal chamber, the bushingincluding an opening; a pin disposed partially in the internal chamberand extending through the opening; and an end cap coupled to the mainbody, wherein the end cap includes a thrust plate and a radial seal,wherein the thrust plate includes apertures configured to receivefasteners.
 2. The equalizer of claim 1, wherein the opening is a firstopening, wherein the end cap includes a second opening, and wherein thepin extends through the second opening.
 3. The equalizer of claim 1,further comprising a garter spring coupled to the radial seal andconfigured to press the radial seal against the pin.
 4. The equalizer ofclaim 1, further comprising an O-ring coupled to a radially exteriorsurface of the end cap.
 5. The equalizer of claim 1, further comprisinga spacer element disposed between the bushing and the end cap.
 6. Theequalizer of claim 5, wherein the spacer element is selected from agroup consisting of a spacer plate, a snap ring, and a rope bead.
 7. Theequalizer of claim 1, wherein the end cap has a disc-like structurehaving an outer diameter that is identical to an outer diameter of themain body.
 8. The equalizer of claim 1, wherein the end cap includes anouter circumferential surface that faces away from the internal chamberand a smaller, inner circumferential surface that faces toward theinternal chamber.
 9. The equalizer of claim 8, wherein the end capincludes a recess defined by a first circumferential surface thatextends transverse to both the outer circumferential surface and theinner circumferential surface, and a second circumferential surface thatextends parallel to both the outer circumferential surface and the innercircumferential surface.
 10. The equalizer of claim 9, wherein therecess extends circumferentially about the pin.
 11. The equalizer ofclaim 1, further comprising lubrication disposed within the internalchamber, wherein the lubrication is at least one of oil or grease, andwherein the lubrication is free to flow around and alongside the pin,and into spaces between the pin and the bushing and throughout theinternal chamber.
 12. The equalizer of claim 1, wherein the main body isa single cast piece.
 13. The equalizer of claim 1, wherein the end capis coupled directly to the main body.
 14. The equalizer of claim 1,wherein the end cap includes a circumferential surface facing theinternal chamber and in abutment with an external surface of the mainbody.
 15. An equalizer for a mining machine, the equalizer comprising:an equalizer main body; an internal chamber defined by the main body; abushing disposed within the internal chamber, the bushing including anopening; a pin disposed partially in the internal chamber and extendingthrough the opening; an end cap coupled to the main body; and a spacerelement disposed between the bushing and the end cap.
 16. The equalizerof claim 15, wherein the opening is a first opening, wherein the end capincludes a second opening, and wherein the pin extends through thesecond opening.
 17. The equalizer of claim 15, further comprising anO-ring coupled to a radially exterior surface of the end cap.
 18. Theequalizer of claim 15, wherein the main body is a single cast piece. 19.The equalizer of claim 15, further comprising lubrication disposedwithin the internal chamber, wherein the lubrication is at least one ofoil or grease, and wherein the lubrication is free to flow around andalongside the pin, and into spaces between the pin and the bushing andthroughout the internal chamber.
 20. The equalizer of claim 15, whereinthe end cap is coupled directly to the main body.